The method normally used to tune a clarinet is to alter the position of the barrel in relation to the top joint. To this end, the clarinet barrel is pulled upwards from the top joint by approx. 1-2 mm. Since the barrel is merely pushed onto the top joint (a corked tenon on the top joint of the clarinet grips into a socket on the clarinet barrel), i.e. the connection is simply of a push-pull type, it is not only difficult to adjust the exact relative position between the clarinet barrel and the top joint to tune the instrument, but there is also a risk that the position of the barrel in relation to the top joint will alter unintentionally.
A further disadvantage of the state of the art is that at the point of transition between the tenon on the top joint of the clarinet that grips into the clarinet barrel and the clarinet barrel itself there is a difference in the diameter of the bore (the internal diameter of the clarinet), creating a gap between the end of the top joint and the clarinet barrel. This causes problems by negatively effecting the intonation of the short notes A and B-flat.
From U.S. Pat. No. 5,249,499 A, a clarinet barrel is known whose effective length can be adjusted to tune the clarinet with 2 threaded parts screwing into each other. The clarinet barrel in U.S. Pat. No. 5,249,499 A consists of a fixed part mounted on the top joint and a threaded ligature that can be screwed into position with the help of the outer casing of the fixed part. In addition, the clarinet barrel to U.S. Pat. No. 5,249,499 A is fitted with a part to be connected to the mouthpiece of the clarinet and which, by means of an extension socket, is inserted into the extension socket of the fixed part. The part of the clarinet barrel to be connected to the mouthpiece of the clarinet carries an outer thread that is screwed onto the inner thread of the threaded part. By rotating the threaded part, the part of the clarinet barrel connected to the mouthpiece is moved towards the fixed part or away from it, depending on the direction of turn, thus shortening or lengthening the clarinet barrel.